Tens of thousands of people across southern and central Ontario remained without power Monday morning as the province’s massive ice storm transitioned to drenching rain.

Provincial power utility Hydro One said its crews were working to reconnect more than 76,000 customers, while Toronto Hydro said the number of customers in the dark had shrunk to 10,000 from about 40,000.

In most cases the crews were dealing with power lines and poles downed by high winds or ice-coated trees that snapped during the storm.

The mix of snow, freezing rain, ice pellets, rain and powerful winds that battered the region Saturday and Sunday made driving treacherous, with provincial police reporting more than 1,450 non-fatal crashes on the highways surrounding Toronto over the two days.

The poor conditions also prompted bus and school cancellations in parts of the province Monday, with schools in Hamilton, Halton and Peel regions closed for the day and buses cancelled in various other districts.

After pumelling Ontario over the weekend, the storm slowly moved east toward Quebec.

By Monday, icy roads were creating slippery conditions in different parts of that province, with schools in the greater Montreal area and further afield closed due to the accumulation of freezing rain.

Hydro-Quebec reported early Monday that more than 33,000 of its clients were without electricity, the majority in the hard-hit Outaouais region in western Quebec and the Monteregie region southeast of Montreal.

The storm also played havoc with air traffic, with more than 600 flights cancelled at Toronto’s Pearson International Airport over the weekend and many others delayed — often for hours. Toronto’s downtown Billy Bishop airport cancelled all departing flights on Sunday and received only one arrival all day.

Some universities and colleges cancelled exams due to the weather, and with heavy rain continuing overnight there were concerns about possible localized flooding. Residents were being urged to try to help mitigate the problem by clearing catch basins of snow and ice.

Meanwhile, police urged drivers to slow down and take extra care, while air travellers were advised to check the status of their flights before heading out.